Photonic jet and its applications in nano-photonics

Photonic jet-an unusually elongated intensive near-field focal point of microspheres-has been utilized for many nano-photonic applications such as novel nanolithography and enhancing light-matter interaction. In microsphere nanolithography, we have realized hexagonal array of arbitrary patterns with sub-80-nm feature size using 254 nm DUV wavelength. This approach provides a high-throughput path for practical production of metamaterial with deep submicron features and over large areas, for a broad range of applications such as thermosphotovoltaics. We have also used the unique properties of the photonic jets to realize monolithic compact hybrid optical antenna with excellent performance in terms of directionality and quantum efficiency. Our results show that quantum efficiencies exceeding 50% and directivity gain of 16 dB are possible. Unlike many near-filed counterparts, the lossless and non-resonant nature of photonic jet makes it uniquely scalable over a broad EM spectrum from deep UV to THz.